Went 8-3 with the Spiteful Druid everyone's running. @ Rank 1 now. 2 losses to the mirror, 1 loss to cubelock. I replaced Mindbreaker with Skulking Geist to counter Taunt Druid / Cubes / Odd Rogues(Cold bloods/Deadly Poison/Hallucinations). Mindbreaker better if you face a lot of Odd Paladins, which I didn't face any, only saw Even Paladin last night, which isn't as big a deal.
I really think Spiteful is just too strong. I had Spiteful coin out on 5, followed by another on 6... get 2 10-drops with 2 4/4.
I had another game with Spiteful on 6 followed by another on 7
So 2 games out of 11 I had back-to-back Spiteful on curve.
My most common 10 drop is Ultrasaur. The 1 time I got a Tyrantus, Rogue had Vilespine. Got Deathwing once also.
It's a ridiculous blowout when you have Spiteful on curve... and moreso if 2.
Also the Druid list is a Keleseth deck, so you add yet another high-roll card if you can play it by turn 2.
Now there are times you just don't draw any of the high rolls, or you end up with your UIs in hand and then Spitefuls/Archavist do nothing, but more often than not you're going to be fine, and you still have Leeroy+Fungal for a minimum 10 damage burst to close out a game.
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All that said, I actually feel like my Token list is a little stronger overall. I beat Spiteful Druid with my Token list the 1 time I played it.. Not much of a sample size though. My Token list mainly loses to cubelock but I'm teching in Skulking Geist into most of my decks these days, so I don't think it's a huge disadvantage anymore.
The Spiteful deck relies on board control with very little comeback mechanics. When I lost to the mirror it's because they had a firm grasp on board and there was nothing I could do.
Tokens have a few comeback mechanics, mainly using Soul of the Forest with Wisps or Plague, but even just a Plague that can stick a few might allow you to buff+roar for a win.